Dual 3" versus single 4"

This is a discussion on Dual 3" versus single 4" within the External Engine forums, part of the LSx Technical Help Section category; Good day,
I have a bit of an exotic car. Its a 2006 Chevrolet Caprice SS, also known as a ...

Dual 3" versus single 4"

Good day,

I have a bit of an exotic car. Its a 2006 Chevrolet Caprice SS, also known as a Holden Stateman / Caprice.

I am in the beginnin stages of my upgrades, but i am at a dilemna. I am ultimately goin with a Twin Turbo setup. and i really dont like wasting money. So how i do my exhaust now will stay even with the last upgrade.

I was thinkin of goin with a Stainless Works dual 3" exhaust for a 2004 GTO with chambered mufflers or custom making my own similar to the Corsa single 3" exhaust but as a 4" with a Borla race muffler.

Here is where i am stoppin, i do not like interior resonates. I DO NOT want to hear my exhaust on the inside. I use to have a 2003 tahoe with a true dual exhaust and i had to keep my window open or else my head would have exploded from the noise pressure. Not the best thing if you are entertaining guests or settin the first impressions.

Presently the engine, @ the flywheel, is at 340hp, later i am hoping to score 420hp with new heads, cam and shorty headers. In my final stages 600hp is my goal. So the 2.5" pips i have now wont cut it.

I know sound and power are related, but there has to be a way to cancel out the interior noise but get the most of the power.

Well, for one thing, sound and power are not related. Yes, most modded cars are louder, but that's what most people like about their sports cars, being loud with their nasty V8's. But there are heavily modded cars out there that are as quite as stock. SLP and flowmaster both make quiet cat-backs for the sound-conscious consumer.

Chambered mufflers aren't going to make things quite, they will do the opposite and give a good musclular tone. My advise is to look up the 'hushpower' muffler from flowmaster (I know, I know, I said flowmaster...) or look into putting in sound-deadening material in the interior.

my 2 cent

If you are doing a twin turbos,what size is the exhaust outlet on the turbos? What ever it is, 1/2 larger on your exhaust piping is right about where any will improvements stop. So if you are using turbos with exhaust outlet 2.5 inch then 3 inch true dual should be all that you need. I can base this rambling off of the average turbo 4 cylinder. up to 500 hp 3inch exhaust.

You asked about 4 inch exhaust I have never used 4 inch exhaust to answer your question with any facts. The only thing I can say is with a single 4 inch exhaust you will have a hard time locating a resonator for it.

Personally I believe in performance cats mainly from Ransom Tech.

So if I were in your dilemna here what I would build (space providing),and assuming you are using turbonectics t3/t4, which are 2.5 exhuast outlet.